1. Field of the Invention
This invention relates to a pumpdown tool for a well, the tool having a circumferential seal and a circumferential centralizer to protect the seal.
2. The Prior Art
With the increased number of offshore wells, more pumpdown tools are being used.
Often the well extends into the earth from the ocean floor at a point remote from the production facilities. Pumpdown tools may be pumped to the well from the production facilities through a flowline lying on the ocean floor. Alternatively, instead of having the flowline on the ocean floor, the well tubing may be highly deviated and the pumpdown tools are pumped through this highly deviated portion of the tubing before entering a relatively vertical portion of the tubing.
Some pumpdown tools have a circumferential seal which, when the tool is landed in a nipple in the well tubing, is adapted to seal with the inner wall of the nipple. While the pumpdown tool is being run through the substantially horizontal flowline on the ocean floor or through a highly deviated portion of the tubing, these resilient seals are nicked, worn, and otherwise damaged. When the tool is landed in the nipple, the seal may be ineffective because of this damage.
Bow springs have been used to centralize tools in a well and to kickover valves into a side-pocket mandrel.